Concrete preparation plant



May 17, 1966 E. E. K UHNER 3,251,584

CONCRETE PREPARATION PLANT Filed Aug. 21, 1965 4 Sheets-Sheet 1 Fig.1

INVENTOR. ERA/57 EwA LD Mia M57 May 17, 1966 E. E. KUHNER 3,251,534

CONCRETE PREPARATION PLANT Filed Aug. 21, 1965 4 Sheets-Sheet 2 INVENTOR. mvsr EWALDKU/M/ER BYWQQDK May 17, 1966 E. E. KUHNER 3,251,534

CONCRETE PREPARATION PLANT Filed Aug. 21, 1963 4 Sheets-Sheet 5 Fig. 4

INVENTOR. cmvsr WALD A u/m/EQ y 7, 1966 E. E. KUHNER I 3,251,584

CONCRETE PREPARATION PLANT Filed Aug. 21, 1963 4 Sheets-Sheet 4 INVENTOR. ERA/57' 54/410 A uHA/ER United States Patent 3,251,584 CONCRETE PREPARATION PLANT Ernst Ewald'Kiihner, Kreuzstrasse 1, Bruchhausen, near Karlsruhe, Germany Filed Aug. 21, 1%3, Ser. No. 304,720 2 Claims. (Cl. 259-154) The invention concerns a concrete preparation plant fitted 'with a feeding device which has several feed openings, said device' for the separate feeding of different aggregates from an adjoining stock, which is divided by means of partition walls into sectoral boxes each terminating in one of the feed openings, as well as with batching devices for aggregates, cementing material and water, and conveying devices for these, and a mixing device.

The usual devices for preparing concrete, consisting of single elements or 'aggregates'assembled on the site, make use of the batter stockpile for storing the variously sized mineral aggregates, with a batching star or batching wall as feeding device. The aggregates are stored in the sectoral boxes radiating from the feeding device. The partition walls of the boxes form acute angles, each of which encloses a lockable outlet of the central feeding device, and through which the aggregates are taken from the stockpile and, if necessary, brought to a bucket weigher, from which are they led to the material hoist of the mixing machine.

Screw conveyors are generally used for conveying th cementing material, in particular cement. The cement is given to the batch mostly from the weigher into the ship of the material hoist of the mixing machine. The dustless feeding of the cementing material directly into the mixer cannot'be realized, since either comprehensive installations are required for this, or the mixer design does not permit of it.

For further transportation, the concrete is generally led from the mixer into crane buckets, agitators or onto road trucks, but also into carts and dumpers or' concrete pumps. The majority of these means of transport can not travel under the discharge opening of the conventionally designed mixer. Also, the capacity of the means of transport is usually greater than one charge of the mixer. A continuous operation of the mixer and the complete output of the plant in conjunction with the means of transport mentioned is to be achieved only in.

combination with a wet or buffer hopper for one or several charges of ready-mixed concrete. For this reason, carpenters or fitters must erect a framework for the mixer on the building site to compensate for this difference in level, and/ or a pit must be dug by the side of the mixer which can take the transport means.

The foregoing review of the position of the engineering of concrete preparation, especially on the building site, shows that, because of the lack of intermediate members, the technical equipment for producing concrete is afilicted with flaws, which necessitate a high degree of improvisatorial knowledge when erecting a concrete preparation plant, as a complete concrete preparation plant requires, according to the present position of engineering, on the building site, and in central plants, a combination of the following single aggregates and building element;

Stockpile for mineral aggregates (batter stock with batchingstar or batching wall);

Conveying means for aggregates (scrapers, material "Mixing device (rotary mixer, open-pan mixer);

3,251,584 Patented May 17, 1966 A further shortcoming in connection with the traditional devices for producing concrete is the high wage rate of trained personnel for erecting and dismantling the entire plant. The single items of equipment comprising the plant are often produced by different manufacturers and, in point of dimensions and capacity, are seldom matched, with the result that functional faults occur during operation. Furthermore, plants of the type mentioned require large ground areas, which are not available, particularly on constrained building, sites in cities. As a result of these circumstances, many building contractors have decided to purchase their concrete from a readymixed concrete plant, waiving the profit to be gained by the concrete preparation.

The invention is based on the proposition of producing a concrete preparation plant fitted with a feeding device which has several feed openings, said device for the separate feeding of different aggregates from an adjoining stock, which is divided by means of partition walls into sectoral boxes each terminating in one of the feed openings, as well as with batching devices for aggregates, cementing material and Water, and conveying devices for these, and a mixing device. According to the invention, all the necessary single aggregates for manufacturing the concrete shall be combined into a complete and transportable unit; it is practical that they shall still be singly capable of dismantling and being exchanged; functions and capacities of the single elements shall be precisely adjusted to one another; erecting and dismantling incurring high wage rate preparatory work shall be limited to a minimum. The plant shall also be space saving, and can therefore be used on medium and small building sites.

According to the invention, a machine frame, serving as a supporting structure, is intended to-be fitted with the batching devices for cementing materal, water and aggregates, a mixing device, as well as conveying and feeding devices, and also drive gears and hand operated or semi or fully automatic control attachments for the work flow;

these parts are joined together andto the machine frame to form a complete transportable whole, within which provision is made for a material hoist for the aggregates and,

if necessary, a screw conveyor for the cementing material as conveying means; the back cutoff-wall of the machine frame serves as dividing wall to the batter stock for the aggregates, which stock is to be constructed about a central angle of approximately this unit is provided with means of batching the aggregates out of the boxes into the material hoist, as well as with means of connecting up the partition walls of the boxes.

' For the purpose of easily exchanging the single parts after the manner of the unit-composed system, according to a preferred design there are devices on the machine "frame, to or on which devices are, in a manner permitting of single dismantling, attached the plant parts manufactured as erection elements, namely Weigh devices for cementing material and water, mixing device, buffer hopper for finished concrete, hoist winch for material 'hoist, scraper winch and protection box with the central electrical installation.

For feeding the cementing material, for example, a

weighing device consisting of a weigher with a weigh bin having a cover can be suspended on carrier rails running r under the roof of the frame. The delivery of the cementing material into the weighing device is effected by means of a screw conveyor lockably suspended on gimbals. The play of the weigher is guaranteed by loosely connecting the weigh bin by means of extensible collars, e.g., of rubber, at the inlet with a discharge support of the screw conveyor, and at the outlet below the cover with a connecting support of the mixing device.

For conveying the aggregates within the plant into the mixer device there is a material hoist provided, consisting of a hoistway arranged essentially vertically and bent at both its ends, a hoist container movable approximately vertically by means of rollers, and a hoist winch. The hoist container .may be fitted with a discharge chute, which opens only in the top end position and then towards the mixing device. The weighing of the aggregates is done by means of an aggregate weigher built into the frame at the base of the hoistway, into which weigher the hoist container travels, said container serving as a weigh bin. For the purpose of giving freedom of movement to the aggregate weigher, the hoisting is interrupted above the aggregate weigher at about the height of the hoist container, the bottom part of the hoistway being rigidly connected to the weigher. This arrangement results in .a particularly small space for the plant.

According to the invention, an open-pan mixer may be used, which consists of a mixing drum and a horizontal drive shaft with mixing tools located on carrier arms. A joining socket arranged on the top of the mixer drum is connected, e.g., by means of a flexible collar, to the weigh bin for cementing material. It is possible to build in other mixer models.

A vent pipe, connected with the air space of the mixer and of the weigh bin, extensible in its length and spanning the weigh bin, is intended as pressure compensation between mixer drum and weigh bin when feeding the ocmenting material to the mixer. The feeding of the aggregates into the mixer can be effected by means of a feed opening facing the material hoist and arranged on the top of the mixer. For measuring the water, a weighing device can be arranged on top of the frame from which the water is led to the mixer through a supply line and spray pipes.

The discharge of the concrete from the mixer may be effected by means of a discharge opening which is pneumatically or hydraulically closed, which opening lies approximately diagonally opposite the feed opening for aggregates, and is in the lower half of the mixer. The discharge can also be effected by tilting the mixer drum.

A buffer hopper can be provided below the discharge opening of the mixer for storing one or several charges of ready mixed concrete.

The partition walls of the boxes of the batter stock, preferably prefabricated, consist of a steel frame formed of U-rails and fillings of corrugated iron plates, and can be put into the rear wall of the machine frame. The profile-sectioned rails lying on the ground in the built-in condition are equipped on the inside of the partition walls of the boxes with locating angles for taking stabilizing planks. The U-profiles of the outer, vertically running rails are directed outwards for taking extension planks.

In order to convey the aggregates in the boxes of the batter stock, a scrape-r winch for moving the handscraper can be provided on the rear of the frame below the winch for the material hoist.

The plant according to the invention may be fitted with singly adjustable parking feet, which are fastened to the machine frame and by means of which the plant can be brought into pl-um b position on uneven ground.

The doors on the weigh devices for cementing material and water, on the mixer, on the buffer hopper and in the through passages from the batter stock to the material hoist can be operated hydraulically or pneumatically by means of corresponding pressure cylinders. For this, a compressor and/or a hydraulic aggregate are provided in the machine frame.

The plant according to the invention can be designed for operation by only one operator. For this, a central control and operation panel, for example, with instruments for controlling the operating cycle, is provided on the machine frame. A further rationalization is possible by means of pa e-adjustable program control devices for the program-controlled manipulation of the entire operating cycle and by meons of additional hand control devices for single or all operations.

Further details and features of the invention will be found in the following description of the relevant schematic drawings of a preferred embodiment of the con crete preparation plant according to the invention.

In the drawings:

FIG. 1 is a front elevation of a concrete preparation plant according to the present invention.

FIG. 2 is a side elevation of the mobile concrete preparation plant of FIG. 1, without the batter stock, having the housing broken away to reveal the internal apparatus.

FIG. 3 is a sectional view taken substantially along line IIIIII of FIG. 2.

FIG. 4 is a plan view of the complete concrete preparation plant of FIG. 1 showing particularly the layout of the batter stock.

FIG. 5 is an enlarged fragmentary horizontal section of the partition walls of the batter stock shown in FIGS. 1 and 4.

FIG. 6 is a front elevation of the plant, without the batter stock, in the transportation position on a mobile carriage.

The concrete preparation plant of this invention consists of the following equipment elements:

A machine frame 1 with weatherproof casing,

A weigh device 2 for the cementing material,

A material hoist 3 for the aggregates,

A mixing device 4,

A buffer hopper 5 for the ready-mixed concrete,

A batter stock 6 and the relevant conveying and batching devices,

A control platform 7 with the necessary checking, control and regulating devices, and

A separate undercarriage 8 for transporting the plant without the batter stock 6.

The machine frame 1 stands on a rectangular base frame 11 with vertically adjustable parking feet 10. Rigidly attached to the base frame is a hoist pit 12, which for its part carries a housing 13, in or to which the remaining equipment elements are arranged. The base frame 11, the hoist pit 12 and the housing 13 form the supporting structure of the plant. The housing 13 is provided with lockable erecting, control and cleaning openings 14; it carries eyes 15 on the roof for lifting gears, and has front bottom transport skids 16a lying somewhat diagonally, which also may serve as sleighs 'when the plant is being transported, and which in conjunction with the guide skids 16b facilitate the planned run-in of concrete buckets 17. The brackets 18 and connecting collars 19 are employed for attachment of the batter stock 6.

The weighing device 2 for the cementing material is fastened to supporting rails 20. Said weighing device consists of a weigher 21, a weigh bin 22 with gate valve 23 and a vent pipe 24. The play of the weigh bin 22 with the weigher 21 is achieved by interruptions in the inlet and outlet of the weigh bin 22 and the vent pipe 24, which are spanned by means of flexible collars 25a, 25b, and 25c. The feeding of the cementing material out of a bin which is not depicted is achieved by means of a screw conveyor 27 in a screw housing 28 with a feed support 2311 and a discharge support 28b, said conveyor mounted on gimbals 26 on the roof of the housing 13 over the inlet to the weigh bin 22, and driven by a motor 29.

The material hoist 3 consists of a hoistway 30 bent at the top and bottom ends, reaching from the base frame 11 up to the height of the weigh bin 22 and running essentially vertically, in which a hoist container 32 provided with rollers 31 is moved by means of a hoist winch 33 and a lifting rope 35 guided over a guide sheave 34a provided with a slackline' switch 34. The hoist container 32 is equipped with a discharge chute 32a, which opens only in the top end position and then towards the mixing device 4. The hoistway 30 is interrupted in the lower third. The bottom part 30a is firmly connected to an aggregate weigher 36 built into the base frame 11. Shock absorbers 37 are provided at the base of the hoist part 30a. The hoistcontainer 32 also serves as weigh bin for the aggregates in the lower position depicted as 32 in FIG. 3.

Below the weighing device 2 and the top end position of the hoist container 32, the mixing device 4 is fitted on guide rails 40, which are fastened at about the height of the horizontal middle line of the housing 13. The mixer illustrated is an open-pan mixer, which consists of a mixer drum 42, a central drive shaft 43, and mixing tools 44 secured to it by means of carrier arms. The shaft 43 is driven by means of motor 45. On the top of the mixer drum 42, and covering the entire Width of the drum, there is a connecting support 46 provided, into which the vent pipe 24 runs, which is connected with the outlet of the weigh bin 22 by means of the flexible collar 25b. Beside the connecting support 46, the dome of the mixer drum exhibits on the side turned towards the material hoist 3, a feed opening 47 for feeding the aggregates out of the hoist container 32. For feeding liquids, a supply line 48 is provided between the connecting support 46 and the feed opening 47, and a spray pipe 48a is distributed over the width of the mixer drum 42. Approximately diagonally opposite the feed opening 47 there is a discharge opening 49a lockable with a flap 49. A pneumatic cylinder 49b is provided for manipulating the flap 49.

On the guide rails 50, below the discharge opening 49a of the mixing device 4, there is fitted a buffer hopper 5 in the form of a funnel 51. The funnel 51 can contain several batches; its bottom end, which carries a gate 53, protrudes out of the housing 13.

Referring to FIG. 4, the rear'wall of the machine frame 1 also serves as a dividing wall for the batter stock 6. This rear wall is provided with brackets 18 and connecting collars 19 for connecting the partition walls 60 which divide the batter stock 6 into boxes.

Within the connecting collars 19 there are arranged, on the rear wall of the hoist pit 12, several through passages 61 beside one another for the aggregates, and provided with gates which are to be operated pneumatically.

- Flexible adjusting chutes 62 lead the aggregates into the 'hoist container 32.

Referring now to FIGS. 1,4, and 5, the partition walls 60 for the boxes consist essentially of frames 6311 designed with U-rails 63 and fillings out of corrugated iron plates 636. The profile-sectioned rails 63 located at the base of the partition walls 60 of the boxes are equipped towards-the inside with locating angles for taking stabilizing planks 64, which also fix the angular distance of the partition walls 60 of the boxes. The U-profile of the outer profile-sectioned rails 63 are turned outwards, so that in case of necessity the batter stock 6 can be enlarged by inserting extension planks 65. The batter stock 6 is bounded in the direction of the hoist pit 12, between the connecting collar 19 and the base frame 11, by means of planks 66.

A scraper winch 67, with a guide block 67a, for a handscraper 68 is pivotably arranged in the top part of the machine frame 1. I

A control platform 7 serves for operating theentire plant. All checking, control and regulating instruments,

as well as program and hand controlled devices, are gathered together in a control and operating panel 70 and can be-manipulated from the operators seat 72 on a platform 73.

An undercarriage 8, as seen in FIG. 6, with pneumatic tires is provided for transporting the concrete preparation plant without the batter stock 6. Raising and lowering or loading and unloading the plant can be done with a winch or a crane. plant on an available fixed point by means of its own hoist winch 33. On the front end of the platform 80 of the undercarriage 8 there are V-blocks 81 fitted, on which the parking feet 10 can be supported. For the most part, the weight of the plant rests on the transport skids 1601.

Of course, within the range of the present invention, there are other modes of execution, inasmuch as they only make use of the basic idea of the invention set forth at the outset.

What is claimed is:

1. A mobile plant for producing concrete enclosed in a housing supported above a movable base frame and having individual devices for handling aggregates, ce-

menting material, and liquids comprising, a mixing device, cement supply means, a weigh bin for cementing material having an attached weighing device, extensible collars connecting said weigh bin to said cement supply means and said mixing device, whereby a measured quantity of cementing material is delivered to said mixing device, a vent pipe connecting said mixing device and said weigh bin for pressure equalization during delivery of the cementing material to said mixing device, liquid batching means providing a measured quantity to said mixing device, a weigher in said base frame, a hoist container selectively seated on said weigher and serving as a batching device for aggregates, a hoistway providing a path for said hoist container from said weigher in said base frame to a discharge position above said mixing device, and a buffer hopper receiving the output of said mixing device and disposed a substantial distance above said base frame to receive conventional concrete transport devices thereunder.

2. A mobile plant for producing concrete enclosed in a housing supported above a movable base frame and having individual devices for handling aggregates, cementing material, and liquids comprising, a mixing device, cement supply means, a weigh bin for cementing material, extensible collars connecting said weigh bin to said cement supply means and said mixing device, whereby a measured quantity of cementing material is delivered to said mixing device, pressure compensating means connecting said weigh bin and said mixing device for pressure equalization during delivery of the cementing material to said mixing device, a spray pipe disposed within said mixing device providing a measured quantity of Water from an external source, a weigher in said base frame, a hoist container selectively seated on said weigher and serving as a batching device for aggregates, a hoistway providing a path for said hoist container from said weigher in said base frame to a discharge position above said mixing de- (References 011 following page) It is possible to erect or lower the- 7 8 References Cited by the Examiner 1,181,410 1/ 1959 France.

IRVING BUNEVICH, Primary Examiner.

3,050,159 8/1962 Paulus et a1. 259154 FOREIGN PATENTS 5 CHARLES A. WILLMUTH, WALTER A. SCHEEL, Examiners.

617,476 4/1961 Canada. R. W. JENKINS, Assistant Examiner. 

1. A MOBILE PLANE FOR PRODUCING CONCRETE ENCLOSED IN A HOUSING SUPPORTED ABOVE A MOVABLE BASE FRAME AND HAVING INDIVIDUAL DEVICES FOR HANDLING AGGREGATES, CEMENTING MATERIAL, AND LIQUIDS COMPRISING, A MIXING DEVICE, CEMENT SUPPLY MEANS, A WEIGHT BIN FOR CEMENTING MATERIAL HAVING AN ATTACHED WEIGHING DEVICE, EXTENSIBLE COLLARS CONNECTING SAID WEIGHT BIN TO SAID CEMENT SUPPLY MEANS AND SAID MIXING DEVICE, WHEREBY A MEASURED QUANTITY OF CEMENTING MATERIAL IS DELIVERED TO SAID MIXING DEVICE, A VENT PIPE CONNECTING SAID MIXING DEVICE AND SAID WEIGHT BIN FOR PRESSURE EQUALIZING DURING DELIVERY OF THE CEMENTING MATERIAL TO SAID MIXING DEVICE, LIQUID BATCHING MEANS PROVIDING A MEASURED QUANTITY TO SAID MIXING DEVICE, A WEIGHTER IN SAID BASE FRAME, A HOIST CONTAINER SELECTIVELY SEATED ON SAID WEIGHER AND SERVING AS A BATCHING DEVICE FOR AGGREGATES, A HOISTWAY PROVIDING A PATH FOR SAID HOIST CONTAINER FROM SAID WEIGHER IN SAID BASE FRAME TO A DISCHARGE POSITION ABOVE SAID MIXING DEVICE, AND A BUFFER HOPPER RECEIVING THE OUTPUT OF SAID MIXING DEVICE AND DISPOSED A SUBSTANTIAL DISTANCE ABOVE SAID BASE FRAME TO RECEIVE CONVENTIONAL CONCRETE TRANSPORT DEVICES THEREUNDER. 